Electronic in-plane symmetry breaking at field-tuned quantum criticality in CeRhIn5

TL;DR

This study provides experimental evidence of electronic nematicity in CeRhIn5, showing field-induced in-plane symmetry breaking near a quantum critical point, which may be linked to unconventional superconductivity.

Contribution

It demonstrates the presence of a nematic phase in a heavy fermion superconductor under high magnetic fields, revealing a potential universal aspect of nematicity in correlated electron systems.

Findings

Field-induced in-plane resistivity anisotropy near quantum critical point

Nematic phase appears without magnetic torque anomalies

Nematicity may be a common feature in unconventional superconductors

Abstract

Electronic nematics are exotic states of matter where electronic interactions break a rotational symmetry of the underlying lattice, in analogy to the directional alignment without translational order in nematic liquid crystals. Intriguingly such phases appear in the copper- and iron-based superconductors, and their role in establishing high-temperature superconductivity remains an open question. Nematicity may take an active part, cooperating or competing with superconductivity, or may appear accidentally in such systems. Here we present experimental evidence for a phase of nematic character in the heavy fermion superconductor CeRhIn5. We observe a field-induced breaking of the electronic tetragonal symmetry of in the vicinity of an antiferromagnetic (AFM) quantum phase transition at Hc~50T. This phase appears in out-of-plane fields of H*~28T and is characterized by substantial in-plane resistivity anisotropy. The anisotropy can be aligned by a small in-plane field component, with no apparent connection to the underlying crystal structure. Furthermore no anomalies are observed in the magnetic torque, suggesting the absence of metamagnetic transitions in this field range. These observations are indicative of an electronic nematic character of the high field state in CeRhIn5. The appearance of nematic behavior in a phenotypical heavy fermion superconductor highlights the interrelation of nematicity and unconventional superconductivity, suggesting nematicity to be a commonality in such materials.